feat(tasks): group extension folder downloads (#1594)

ui/flutter/test/features/tasks/application/tasks_controller_test.dart

@@ -0,0 +1,80 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:gopeed/api/model/task.dart' as api;
+import 'package:gopeed/core/capabilities/app_capabilities.dart';
+import 'package:gopeed/core/capabilities/capability_rpc.dart';
+import 'package:gopeed/core/capabilities/gopeed_capability.dart';
+import 'package:gopeed/features/tasks/application/tasks_controller.dart';
+
+void main() {
+  test('the list counts a group once and sends group IDs for every action', () async {
+    api.Task task(String id) => api.Task.fromJson({
+      'id': id,
+      'name': '$id.txt',
+      'group': {'id': 'group', 'name': 'folder', 'path': '/downloads/folder', 'createdAt': '2026-01-01T00:00:00Z'},
+      'parentId': 'group',
+      'protocol': 'http',
+      'status': 'pause',
+      'uploading': false,
+      'createdAt': '2026-01-01T00:00:00Z',
+      'updatedAt': '2026-01-01T00:00:00Z',
+      'meta': {
+        'req': {'url': 'https://example.com/$id'},
+        'opts': {'path': '/downloads/folder', 'size': 100},
+      },
+      'progress': {'used': 0, 'speed': 0, 'downloaded': 25, 'uploaded': 0, 'uploadSpeed': 0},
+    });
+    final raw = [task('first'), task('second')];
+    final actions = <String>[];
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getTasks, (_) => raw)
+      ..bind(GopeedMethods.pauseTask, (id) {
+        actions.add('pause:$id');
+        return const RpcUnit();
+      })
+      ..bind(GopeedMethods.continueTask, (id) {
+        actions.add('resume:$id');
+        return const RpcUnit();
+      })
+      ..bind(GopeedMethods.pauseTasks, (params) {
+        actions.add('pauseBatch:${params['ids']}');
+        return const RpcUnit();
+      })
+      ..bind(GopeedMethods.continueTasks, (params) {
+        actions.add('resumeBatch:${params['ids']}');
+        return const RpcUnit();
+      })
+      ..bind(GopeedMethods.deleteTasks, (params) {
+        actions.add('delete:${params['ids']}:${params['force']}');
+        raw.clear();
+        return const RpcUnit();
+      });
+    final container = ProviderContainer(
+      overrides: [appCapabilitiesProvider.overrideWithValue(AppCapabilities(LocalCapabilityInvoker(registry)))],
+    );
+    addTearDown(container.dispose);
+    final state = await container.read(tasksControllerProvider.future);
+    expect(state.tasks.length, 1);
+    expect(state.tasks.single.members.length, 2);
+    expect(state.allTasks.map((task) => task.id), ['group', 'first', 'second']);
+    expect(state.findTask('group'), same(state.tasks.single));
+    expect(state.findTask('first'), same(state.tasks.single.members.first));
+    expect(state.findTask('missing'), isNull);
+    expect(state.tasks.single.matchesSearch('second.txt'), isTrue);
+    expect(state.tasks.single.progress, 0.25);
+    final controller = container.read(tasksControllerProvider.notifier);
+    await controller.pause('group');
+    await controller.resume('group');
+    await controller.pauseAll(['group']);
+    await controller.resumeAll(['group']);
+    await controller.deleteSelected(['group'], force: true);
+    expect(actions, [
+      'pause:group',
+      'resume:group',
+      'pauseBatch:[group]',
+      'resumeBatch:[group]',
+      'delete:[group]:true',
+    ]);
+    expect(container.read(tasksControllerProvider).value?.tasks, isEmpty);
+  });
+}